The one is noradrenaline neurons in the locus coeruleus of the brain, suppressing strong sleepiness, and the other is serotonin*4 neurons in the dorsal raphe nucleus of the brain, inhibiting cataplexy. (eurekalert.org)

While cataplexy worsens with fatigue, it is different from narcoleptic sleep attacks and is usually, but not always, triggered by strong emotional reactions such as laughter, anger, surprise, awe, and embarrassment, or by sudden physical effort, especially if the person is caught off guard. (wikipedia.org)

A study in 2006 in "Tohoku Journal of Experimental Medicine" concluded that the neurochemical hypocretin, which is regulated by the hypothalamus, was significantly reduced in study participants with symptoms of cataplexy. (wikipedia.org)

In this review, we will specifically focus on cataplexy and describe its clinical features, its association with the neurotransmitter hypocretin and the human leukocyte antigen DQB1*0602, as well as treatment options. (scholarpedia.org)

The trial showed that pitolisant, which has previously shown to be active against EDS, was also able to significantly reduce cataplexy when given once-a-day for two months in severely affected patients. (practicalneurology.com)

Data from the Stanford University Sleep Disorders Clinic of 200 patients with cataplexy showed that 100 percent of these patients reported laughter as the most common trigger, followed by a feeling of amusement, or surprise with happiness and joy . (scholarpedia.org)

Cataplexy also occurs more frequently in times of emotional stress and when patients are deprived of napping while sleepy. (scholarpedia.org)

This study has revealed that serotonin neurons do not directly suppress muscle tone weakening but inhibit cataplexy by reducing and controlling activities of the amygdala, which is involved in communicating emotional excitement. (eurekalert.org)

Cataplexy is an episodic loss of muscle function, ranging from slight weakness such as limpness at the neck or knees, sagging facial muscles, weakness at the knees often referred to as "knee buckling", or inability to speak clearly, to a complete body collapse. (wikipedia.org)

A study by Anic-Labat et al reported that emotions arising from "hearing or telling a joke," "laughing," or "when angry," were most predictive of the loss of muscle function in clear-cut cataplexy . (scholarpedia.org)

Tricyclic antidepressants (TCAs) are often effective in controlling cataplexy, but also frequently produce side effects that limit their use. (rxlist.com)

Zimelidine was reported by Montplaisir and Godbout to be very effective for cataplexy in 1986, back when this was usually controlled by tricyclic antidepressants, which often had anticholinergic effects. (wikipedia.org)